PECVD a-SiC:H thin films from liquid organosilanes dependence of photoluminescence on starting material

The dependence of the photoluminescence (PL) properties of plasma deposited a-SiC(N):H films on the starting material is discussed in this paper. A model of the growth process based on the infrared absorption spectra and plasma parameters is developed and used to explain the differences in the PL. The PL maximum for films we made from liquid organosilane feed stock, varied between 490 nm (2.5 eV) and 410 nm (3.0 eV). In this paper the PL and structure of films produced from hexamethyldisilane (HMDS) with a PL maximum at 450 nm (2.75 eV) and of films produced from hexamethyldisilazane (HMDSN) peaking at 410 nm (3.0 eV) are discussed. The differences in PL are attributed to the different microstructures of the films which result from the starting material. This structural difference is indicated by different absorptions for Si–(CH3)2, Si–(CH3)3 and Si–CH2–Si in the infrared absorption spectra of the two starting materials.